Pagine

What is stereo?

There are now two system of high fidelity, monophonic (monaural) and stereophonic. Monophonic is a system that starts from one microphone and is fed through a single high fidelity set. Stereophonic is a double system. Two separate microphones are placed at different sides of the orchestra and two different systems are used to keep the two signals or channels separated. Two separate speakers are used, placed on different sides of you room. Stereo is much like 3-D photography, two slightly different sound reach your ears giving you a new dimension in sound.

A main
monitor system for Recording and Post-production studios where the requirement
is for high performance, natural sound reproduction. With a single coherent
wavefront thanks to the 15" Dual Concentric™ point source driver, sound
presented to the engineers is remarkably distortion free. And with the enlarged
monitoring position provided by this remarkable drivers wide dispersion,
monitoring with the System 15 DMT II is particularly fatigue free.

The
availability of new materials and manufacturing processes has allowed Tannoy to
design the System 15 DMT II from first principles, producing an all new Dual
Concentric™ monitoring system with all the classic benefits of single point
source monitoring combined with an exceptionally detailed but fatigue-free
sound.

The style of
the cabinet is not arbitrary, it has been arrived at by considering the
acoustic principles of diffraction and energy storage.

The trim
rings around the rubber surrounds are there to smooth out the otherwise
discontinuous contour to the HF wavefront.

The smooth
lines around the port tubes ensure laminar air flow at low frequencies where
the air in the ports has maximum velocity.

The shapes
of the LF cones continue the hyperbolic waveguide for the HF energy
propagation.

The cabinet
bracing and internalconstruction ensures that the HF unit can deliver the
detail into the sound field.

The
application of the Differential material Technology approach to component
behaviour ubder vibration and magnetic fields has lead to custom crossover
components, custom cabling and split crossovery design being employed.

Designed for
close field monitoring applications, the diminutive KRK Model 6000 has
inherited the sonic characteristics of the KRK Model 7000B, the industry
standard compact monitor for top-of-console placement. The most competitively
prieced close-field monitor to join the renowend KRK line, the 6000s utilize
the latest in aerospace materials and the highest quality components. The
monitor is also available in a video shielded version ,the6000S.

The
components are comprised of a 6-inch polyglass woofer and a 1-inch Kevlar
inverted dome-tweeter. The system is crossed over at 2,4 kHz with a passive
crossover network. The KRK 6000 can handle up to75 continuous watts and has a
maximum SPL of 106 dB, which is more than adeguate in near-field applications.

Perfect for
all close-field applications, the KRK 6000s delivery an extremely smooth
frequency response with very low distortion. Their small size and weight of only 18 lbs, each make them extremely
portable for independent engineers who like to move their own reference
monitors from studio to studio.

The McIntosh
Tuner-Preamplifier unit concept accommodates all regular inputs of tuner,
phono, tape, etc.,and allows the
selection of the right power amplifier needed for your system. The MX 113
is the most advanced version of this remarkable AM-FM/FM Stereo Tuner
preamplifier with switchable selectivity. It has performance beyond any other
manufacturer's equipment available today.

Special
Features

Multiple
"selectivity" switchable from the front panel. An elegant solution to
a tough problem.

Linear Phase
(constant delay) IF amplifier for low distortion at even high selectivity and
low distortion.

Highest
spurious rejection 90 dB (IHF) and highest image rejection 95 dB (88 to 108
MHz). This means you receive the stations at the right place on the dial only.
You don't receive the same stations or some mixture as you tune across the
dial.

McIntosh
developed a special detecting circuit used in the multiplex section. An
advantage of this circuit is the elimination of the critical adjustments
necessary with commonly used matrixing circuits. The circuit detects the L - R
side-bands, then automatically matrixes the recovered information with the L +
R carrier signal. This yialds the left and right program output with maximum
separation.

TUNING
MECHANISM AND DIAL DRIVE

In the MX
113, the unique design and careful manufacture of the mechanical assembly gives
smooth flywheel tuning. By controlling the relationship of mass and mechanical
resistance, and by dividing the workloads in the dial drive system, it becomes
nearly impossible to detect any backlash. Yet, the entire dial drive is a model
of mechanical stability. For added ease and increased tuning accuracy, a
section of the dial pointer is illuminated.

FM SECTION

The Radio
Frequency (RF) section houses the complete FM-RF front-end and part of the AM
RF circuit. A seven-section variable capacitor is the heart of the RF section.
Four sections of the variable capacitor are in the FM front end and the
remaining three are in the AM section. By interleaving the sections
(AM-FM-AM-FM-etc.) spurious responses are significantly reduced. The four FM
sections of the variable tuning capacitor provides a high degree of RF
selectivity and excellent spurious rejection. Using the latest "state of
the art" field effect transistors with a welldesigned variable tuning
capacitor has provided the MX 113 with an excellent RF front-end ….

FM-IF AND
DISCRIMINATOR SECTION

The MX 113
uses linear-phase IF filters. Each filter was designed from a FORTRAN computer
program for minimumphase and constant delay. The mathematical complexity of the
filter design procedure is almost beyond belief. Using numerical integration in
the S-Plane, an "IBM" 1130 high speed computer spent eighteen minutes
on the mathematics for the design of the IF filter. It would have taken a human
engineer, working twenty-four hours a day, seven days a week, and working
error-free three-hundred years to perform the same mathematical calculations!
...

FM STEREO
MULTIPLEX SECTION

Mclntosh has
developed a special detecting circuit used in the multiplex section. A
particular advantage of this circuit is the elimination of the critical
adjustments necessary with commonly used matrixing circuits. The circuit
detects the L - R sidebands, then automatically matrixes the recovered
information with the L + R carrier signal. This yields the left and right
program output with maximum separation. ...

AM SECTION

The AM-RF
amplifier circuit includes a three section variable tuning capacitor in the
metal enclosed shielded RF module which also houses the FM-RF front end. A
three section variable capacitor is used for greater spurious rejection. The RF
amplifier is unique. The circuit has constant sensitivity, constant
selectivity, high image rejection across the complete AM band. Ordinary AM-RF
circuits cannot do all of these simultaneously. This circuit design achieves
equal sensitivity even at the low end of the band. Spurious, image, and
intermediate frequency rejection are all superior. The same circuit delivers
equal selectivity across the entire band. The Mclntosh circuit is unique in a
superheterodyne AM receiver ...

...The AVC
(automatic volume control) system was designed to prevent bursting or thumps
when the AM is tuned through a strong signal. Distortion at low audio
frequencies is minimized by using two AVC filter sections instead of the
conventional one.

PHONO
PREAMPLIFIER

There are
three transistors in each channel of the phono preamplifier. The output of the
third transistor is connected by a negative feedback loop to the emitter of the
input transistor. The feedback loop reduces noise and distortion. It also
provides precision RIAA frequency compenation required for magnetic phonograph
cartridges. Feedback remains in effect even at 20 Hz, where gain is highest.
The negative feedback also provides a low output impedance for the tape output.
...

L + R
AMPLIFIER

The L + R
amplifier consists of a single transistor connected as a voltage amplifier.
Negative feedback is used around the summing amplifier to maintain low
distortion and provide a low impedance for the center channel output.

POWER SUPPLY

The power
supply of the MX 113 has received very special attention.

Three
separate rectifier circuits are used. First, a fullwave rectifier supplies DC
to all audio circuits. The second full-wave rectifier supplied DC to all tuner
and multiplexdecoder circuits. The third supply provides DC to the AM circuit.
The power supplies are elaborate in design. They use electronic filtering to
insure the lowest possible background hum level, maximum stability, and
extremely good regulation.

Specifications

FM
Section

Useable
Sensitivity: 2.5 microvolts at 100% modulation (± 75 kHz deviation) for less than 3% total noise and harmonic
distortion,

Volume
Control: Precision "tracked" at al l listening levels. (0 to —65
dB). Does not change stereo balance as loudness is changed. The AC power ON/OFF
switch is coupled with this control.

Balance
Control: Natural balance at center position, attenuation of left or right
channel by rotating control.

Loudness: Loudness compensated or flat
response—Loud- ness position
boosts low frequencies for low level listening. Operates as a function of
volume control position. Full compensation is obtained at lower volume levels
and flat response is obtained at full volume.

Selectivity: Increases
the ability of the tuner to separate a weak (distant) station from a strong
(local) station on adjacent channels.

Mode: Selects
either stereo or mono operation

Phase
Control: Electronically reverses phase in the left channel to correct
"out of phase" program sources. MUTING: Suppresses the background
noise and hiss normally heard between FM stations.

Tape
Monitor: Pushbutton; compares recorded tape with program source while
recording.

Muting
Adjust: Modifies the noise rejection threshold on

FM Dial Scale Intensity: Modifies the brightness of the illumination of the front
panel

Widely
acclaimed throughout the world for its superb craftsmanship, the ReVox tape
recorder is now available for the first time in U.S. and Canadian markets. The
discriminating audiophile is well aware that there can be no compromise with
quality and that the excellence of tape recordings is directly dependent on the
skill and care used in the manufacture of their tape recorder. Quality control,
constant checking and testing during every phase of ReVox manufacture and the
use of highly rated components are the hallmarks of this superior instrument. ReVox is
backed by a tradition of almost two decades in the manufacture of studio and
broadcast tape equipment. The experience gained has resulted in ideas which
have been incorporated into each ReVox. The ReVox, the instrument of choice by
amateur and professional tape recordists, is also used in numerous industrial
applications, in universities, as a teaching aid.. And as the focal point in
home entertainment centers.Its
applications are seemingly limitless. Its quality is singular.

Professional
Features of the ReVox

Push-button
electrical control of all operating modes.

Spool
turnscounter.

Remote
control facility.

Recorder can
be used as an amplifier by switching off the capstan motor.

Three motors
are usually found only in professional tape recorders. This rather costly
design assures optimum performance especially regarding to wow and flutter, and
it is mechanically simple without containing any fast wearing parts.

A design unique for an amateur recorder. Consisting of five
diecastings, these parts, when attached to one another, from the very rigid
unit which carriesthe head-block and
tape-guides. This assures perfect and permanent head alignment under the
roughest operating conditions. The powerful Hysteresis-Synchronous-Motor and
the heavy accurately balanced flywheel are mounted in a diecast cage. The
runout of the capstan shaft must not exceed 0,001 mm in order to pass inspection.
This is a degree of accuracy found only in studio an broadcast equipments.

6/12
Hysteresis-SynchronousMotor

The
heavy-duty direct drive capstan motor is a hysteresis synchronous unit. The
speed is electrically changed by controlling the number of poles. Maximum
playing time can be had by setting the tape speed at 33 ¾ ips or superior quality by using a tape speed
of 7 ½ ips.

Anti-Wow ans
Anti-Flutter Design

The speed of
the heavy-duty Pabst motor for the capstan is locked in with the power-line
frequency, assuring remarkable uniformity of capstan shaft speed rotation. The
motor is completely shielded, eliminating any stray megnetic motor flux.
Precision bearings on the drive shaft removes the lateral pressure caused by
the pinch roller and protect the motor from any uneven load.

Tape
reels Up to 10 ½" Diameter

Maximum
recording or playback time is assured through the use of reels having a
diameter of 10½". These reels
will accommodate up to 4800 feet of Lptape. Rewind can be accomplished in a few
moments. Tape tension is controlled with a simple, easily operated, readily
accessible control, which is designed so that large reels cannot be placed into
position when it is set for reduced tape tension.

Separate
VU-meters for each channel

The
VU-meters on the ReVox are precision instruments with dynamic characteristics
as required by the A.S.A. in the standard for volume measurement of complex
waves. Accurate control of recording level is possible. Scale illumination of
these meters is switched with the channel selector for added operating
convenience.

Solenoid
Operated, Oversized Brakes

The brake
bands are lifted off the linings during any operating mode. The required tape
tension is achieved electrically by counter-torque on the winding motors. This
assures minimum wear of mechanical parts. Braking is quick and positive from
fast wind, even in the event of power failure.

Mechanical
tape Stop

Because of
the very fast winding speeds used by the ReVox, the instrument does not depend
on metal contacts for stopping the recorder. A microswitch senses the end of
the tape and turns off the motor circuits automatically after a real has been
rewound. Automatic motor shutoff also takes place when a tape splice has
opened.

Bulit-in
Mixing Facilities

The mixing
arrangements provide for the one pre-amplifier not in use for recording to be
coupled with the other pre-amplifier through which the recording is being made,
with neither gain control acting as a master. Thus any two signals may be mixed
and recorded in the mono mode. The same controls are used for adjusting level
and balence when recording stereophonically. Additionally, one channel can be
set to playback while the other recording and all forms of sound-on-sound and
sound-with-sound are possible.

Separate
record and Playback - Amplifiers for both channels

The record
amplifier hs a reserve gain of 14 dB before any distortion. Through the used of
separate heads for record and play, continuous monitoring becomes possible.

Hum level

Every effort
has been made to keep hum at an absolutely minimum level. The first stages of
the amplifier have D.C. heated filaments. Teh power transformer has a grain
oriented strip-wound core providing a minimum of stray magnetic field, reducing
hum pickup.

With the use of three motors the ultimate in simplicity can be
achieved. Two motors for winding and rewinding and a third, the Capstan motor,
for smooth and even tape transport during recording and replaying. There are no
belts - other than that for the counter - no levers and no gears required for
engaging the various operating modes

A glance at the amplifier chassis revoalscomponents of the highest
quality not gonerally found in home equipment. Simple and easy to follow wiring
takes the problems out of servicing.

Tubes

In addition
to three silicon diodes and three selenium rectifiers, the ReVox uses a total
of twelve dual function tubes. Each stage has been designed for single function
operation. No simplification, with attendent tachnical compromise, has been
permitted.

The world's
most accurate and reliable tuning device, obsoletes center-tuning meters by
employing a digital computer to automatically flash an indicator panel light
when best tuned for maximum reception (absolute center channel and lowest
distortion).

True AM high
fidelity

After years
of costly experimentation, Scott engineers discovered the answer underlying
true Am high-fidelity. Distortion so low that Scott AM is virtually
undistinguishable from FM. Employing latest FET and Integrated Circuit
techniques in the 3300, they throughly eliminated interference and drift. Weak
stations now assume a new clarity, strong stations become totally
distortion-free, and a new FET mixer improves cross modulation rejection and
cuts adjacent stationinterference.

Solderless
wire connections

A scott
exclusive, "tension wrap" each wire around a terminal under
tremendous torsion. Consequently, the 3300 possesses a dependability akin to
aerospace and computer applications because the problems of cold or unsoldered
connections are drasticly reduced.

In the tuner
IF section never requires realignment or adjustment. Never … regardless of age
or operating temperature. This revolutionary feature, never found before in
receivers in this price range, also yields the extra divident of very low
distortion and incredible selectivity.

F/C/O
Circuity

Provides
close to distortion-free listening, even at low volume levels. The 3300
incorporates Full Complementary Output Transistors to achieve perfect
undistorted sound, over a wide power bandwidth at both 8 and 4 ohms … a vital
factor when connecting extra speakers.

Here is of
the traditional quality, value and features for which Sherwood is famous - at a
modest price. An unparalleled command center for the finest high-fidelity music
systems, the S7100 feature power to spare for even the most inefficient speaker
systems, and distortion at listening levels is a mere 0,20%.

Sherwood's
unique front panel tape jack (plus rear panel tape jacks) allows simultaneous
recording on two records or dubbing from one recorder to another. Stereo
headphone jack, too, for private listening. Speaker
selector switch permits listening to your main set of stereo speakers (A) a
remote set of stereo speakers (B) or both sets at the same time (A&B).

Tuning your
favorite FM or Am stations is a joy with Sherwood's velvet touch "Flywheel
tuning;" signal strength meter pinpoints when you are properly tuned to
your station and a "Stereo" indicator light tells you if you are
listening to a stereo station. The S7100
achieves a reliability of performance backed by a full 3-year warranty on all
parts. And Sherwood packages this superlative receiver in a distinctively
styled handsome walnut cabinet, included at no extra cost. Whatever your wants
- power, performance, beauty - Sherwood paces the field.

Features:

Hermetically
sealed microcircuit, FET circuitry

Front panel
extra Tape record/dubbing jack

FM
"Hush" muting circuit

Handsome
walnut case included

Specifications

FM Tuner
Section

FM
Sensitivity (IHF): 1,9 µV (-30 dB
noise&dist)

Signal-to-Noise
Ratio: -65 dB

Capture
Ratio: 2,8 dB

Suppression
of AM: -50 dB

Tuning
Range: 87,5 to 108,5 MHz

Distortion: 0,5% at 100% Mod.

Spurious
Response Rejection: -87 dB

Stability: ±15 kHz (±0.015%)

Image
Rejection: -78 dB

IF
Rejection: -90 dB

Alternate
Channel Selectivity: 40 dB

Stereo
Separation: 40 dB at 1 kHz

Frequency
Response [Stereo]: 20 - 15,000 Hz ±1 dB

Antenna: 300 Ω balanced

AM Tuner
Section

Sensitivity:
5 µV at 60% mod. For 6 dB S/N

Selectivity: 7,5 kHz at -6 dB

Frequency
Response: -6 dB at 4,0 kHz

Tuning
Range: 530 to 1625 kHz

Image
Rejection: -50 dB at 1mhz

Antenna:
Ferrite Rod (rotatable), High Imp. Input

Amplifier
Section

Power Output

At 4 Ω : Music Power 80 W Total - Equivalent Music
Power ±1 dB 100 watts RMS Power 30 watts X2

At 8 Ω : Music Power 70 W Total - Equivalent Music
Power ±1 dB 85 watts RMS Power 25 watts X2

Increased
efficiency in our new factory, together with new production methods, have
enabled us to introduce the new RD80 into a price range much lower than was
hitherto thought practical for a quality turntable. The RD80
maintains the Ariston philosophy of excellence of design, together with top
class performance. It has the capacity to extract the maximum amount of
information from the disc.

Like our
other models the RD80 is entirely gimmick-free, and provides simply the best
platform for carrying a vinyl disc without allowing that disc or any other
extraneous energy sources to interfere with the stylus-to-groove interface.

The RD80 -
quite the finest value turntable available "today".

" At something
like 2/3 the cost of its luxury finish brother the 110 , the RD80 sacrificies
little considering the price difference. The finish is plainer, but nonetheless
the plinth is wood veneered and the machined alloy pkatter weighs 2,45 kg. A
single large pulley and foolprof drive runs at a 33-1/3 rpm via a conventional
rubber belt, the three point sprung steel subchassis successfully isolating the
platter/arm system from environmental disturbance.

Although
improved since last reviewed, setting up is still time consuming, though helped
by using underside bolts accessible without removing the bottom cover. Possibly
as a result of the reduced platter mass, this deck was more stable in its set
up and remained so for longer than the Rd110. The plinth will accept some of
the longer arms, and the lid is a generously thick dark-tinted PVC moulding."

"Performingwell
on the labtests, wow and flutter, torque, rumble, start up time and speed error
were all very good for the class and type of deck.A trace of 100 Hz motor breakthrough was
however present, measuring -65 dB unweighted.The sensible flat mat gave an above average disc impulse result.If anything its isolation and acoustic
rejection were superior to those of the 110, probably because of the more
stable subchassis behaviour, and good to very good results were obtained here.

Sound
Quality

In tonal
balance the RD80 was judged quiete good with a well integrated character, if
slightly dull. The sound field was quitesecure and stable,demonstrating fairly good bass as well as a precise
image, with good focus and fair depth - all strong plus points at the price."

Resonance
Isolation

Optimum
resonance isolation is achieved in all Ariston turntables. Relatively slow
running AC syncgronous 24-pole motors now extensively used in audiophile
turntables were first introduced by Ariston in 1969. the motor are completely divorced from the
subchassis and tone arm assembly. All frequencies are therefore contained
within an innocous area.

The
Sub-Chassis

We construct
the sub-chassis in precision pressed heavy gauge steel or aluminium which is
perfectly flat on all planes. The
bearing housing and the tone arm board are rigidly mounted to the sub-chassis.
The entire assmbly is isolated and has a natural frequency in the area of 4 Hz.

The Tone Arm
Board

The Ariston
tone arm board is protected from
damaging infrasonic frequencies in the area of 7 - 16 Hz, which are set up by
the arm's oscillation. These frequencies are moved to a lower harmless value by
the use of acoustically dead materials.

The Platter

All Ariston
platters incorporate peripheral mass distribution which, by maintaining a
flywheel effect, smooth out the undesirable effects of wow and flutter. It should also be noted that the parameters
of wow amd flutter by which turntables are commonly judged, does not indicate
the turntable.s ability to retrieve information.

The Belt
Drive

In a
no-compromise turntable, designed for maximum isolation, any other method of
drive is totally unacceptable. The flat neoprene belt precision ground to a
fine finish isolates the disc-carrying platter from the motor. A flat belt is
employed for absolute speed stability - a round belt can twist and thereby
create wow. Direct drive does not
isolate, due to the fact that it cannot be de-coupled from the platter. This
creates resonance at the vinyl/stylus interface.

The Main
Bearing

Our shaft
bearing is unoque. Before we go on to explain why, it would be helpful for you
to remember that a piece of cigarette paper measures one thousandth of an inch
in thickness.

The bearing
has to eliminate vertical movement which manifests itself as rumble (a low
Growl) through the speakers. Ariston turntables have a typical rumble figure of
-74 dB weighted. Any figure in excess claimed by other manufactures must be
treated with some degree of scepticism due to the environment and the
inadequacies of test equipment currently available.

The shaft is
precision ground from hardened high tensile chrome steel to within a tolerance
of ± .0003 inches. That is two tents of one thousendth of an inch. One fifth
the thickness of a cigarette paper.

The surface
finish is a mirrorlike 4 - 6 microns and the hardness is to 64° rockwell.

The shaft
rest on a spherically precise captive ball for single point contact.

The bearing
hpusing is honed to perfectly amtch the shaft.

Take the
belt off an Ariston turntable and turn the hub and platter by hand.

Note how
friction free the entire assembly is - it
will simply run on and on and on.